assign_number is added as a member of sctp_stream_interleave, used
to assign ssn for data or mid (message id) for idata, called in
sctp_packet_append_data. sctp_chunk_assign_ssn is left as it is,
and sctp_chunk_assign_mid is added for sctp_stream_interleave_1.

This procedure is described in section 2.2.2 of RFC8260.

All sizeof(struct sctp_data_chunk) in tx path is replaced with
sctp_datachk_len, to make it right for idata as well. And also
adjust sctp_chunk_is_data for SCTP_CID_I_DATA.

After this patch, idata can be built and sent in tx path.

Note that if sp strm_interleave is set, it has to wait_connect in
sctp_sendmsg, as asoc intl_enable need to be known after 4 shake-
hands, to decide if it should use data or idata later. data and
idata can't be mixed to send in one asoc.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To avoid hundreds of checks for the different process on I-DATA chunk,
struct sctp_stream_interleave is defined as a group of functions used
to replace the codes in some place where it needs to do different job
according to if the asoc intl_enabled is set.

With these ops, it only needs to initialize asoc->stream.si with
sctp_stream_interleave_0 for normal data if asoc intl_enable is 0,
or sctp_stream_interleave_1 for idata if asoc intl_enable is set in
sctp_stream_init.

After that, the members in asoc->stream.si can be used directly in
some special places without checking asoc intl_enable.

make_datafrag is the first member for sctp_stream_interleave, it's
used to make data or idata frags, called in sctp_datamsg_from_user.
The old function sctp_make_datafrag_empty needs to be adjust some
to fit in this ops.

Note that as idata and data chunks have different length, it also
defines data_chunk_len for sctp_stream_interleave to describe the
chunk size.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sctp_idatahdr and sctp_idata_chunk are used to define and parse
I-DATA chunk format, and sctp_make_idata is a function to build
the chunk.

The I-DATA Chunk Format is defined in section 2.1 of RFC8260.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds intl_enable in asoc and netns, and strm_interleave in
sctp_sock to indicate if stream interleave is enabled and supported.

netns intl_enable would be set via procfs, but that is not added yet
until all stream interleave codes are completely implemented; asoc
intl_enable will be set when doing 4-shakehands.

sp strm_interleave can be set by sockopt SCTP_INTERLEAVING_SUPPORTED
which is also added in this patch. This socket option is defined in
section 4.3.1 of RFC8260.

Note that strm_interleave can only be set by sockopt when both netns
intl_enable and sp frag_interleave are set.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As rfc3758#section-3.1 demands:

   A3) When a TSN is "abandoned", if it is part of a fragmented message,
       all other TSN's within that fragmented message MUST be abandoned
       at the same time.

Besides, if it couldn't handle this, the rest frags would never get
assembled in peer side.

This patch supports it by adding abandoned flag in sctp_datamsg, when
one chunk is being abandoned, set chunk->msg->abandoned as well. Next
time when checking for abandoned, go checking chunk->msg->abandoned
first.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces RFC Draft ndata section 3.2 Priority Based
Scheduler (SCTP_SS_RR).

Works by maintaining a list of enqueued streams and tracking the last
one used to send data. When the datamsg is done, it switches to the next
stream.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces RFC Draft ndata section 3.4 Priority Based
Scheduler (SCTP_SS_PRIO).

It works by having a struct sctp_stream_priority for each priority
configured. This struct is then enlisted on a queue ordered per priority
if, and only if, there is a stream with data queued, so that dequeueing
is very straightforward: either finish current datamsg or simply dequeue
from the highest priority queued, which is the next stream pointed, and
that's it.

If there are multiple streams assigned with the same priority and with
data queued, it will do round robin amongst them while respecting
datamsgs boundaries (when not using idata chunks), to be reasonably
fair.

We intentionally don't maintain a list of priorities nor a list of all
streams with the same priority to save memory. The first would mean at
least 2 other pointers per priority (which, for 1000 priorities, that
can mean 16kB) and the second would also mean 2 other pointers but per
stream. As SCTP supports up to 65535 streams on a given asoc, that's
1MB. This impacts when giving a priority to some stream, as we have to
find out if the new priority is already being used and if we can free
the old one, and also when tearing down.

The new fields in struct sctp_stream_out_ext and sctp_stream are added
under a union because that memory is to be shared with other schedulers.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces the hooks necessary to do stream scheduling, as
per RFC Draft ndata.  It also introduces the first scheduler, which is
what we do today but now factored out: first come first served (FCFS).

With stream scheduling now we have to track which chunk was enqueued on
which stream and be able to select another other than the in front of
the main outqueue. So we introduce a list on sctp_stream_out_ext
structure for this purpose.

We reuse sctp_chunk->transmitted_list space for the list above, as the
chunk cannot belong to the two lists at the same time. By using the
union in there, we can have distinct names for these moments.

sctp_sched_ops are the operations expected to be implemented by each
scheduler. The dequeueing is a bit particular to this implementation but
it is to match how we dequeue packets today. We first dequeue and then
check if it fits the packet and if not, we requeue it at head. Thus why
we don't have a peek operation but have dequeue_done instead, which is
called once the chunk can be safely considered as transmitted.

The check removed from sctp_outq_flush is now performed by
sctp_stream_outq_migrate, which is only called during assoc setup.
(sctp_sendmsg() also checks for it)

The only operation that is foreseen but not yet added here is a way to
signalize that a new packet is starting or that the packet is done, for
round robin scheduler per packet, but is intentionally left to the
patch that actually implements it.

Support for I-DATA chunks, also described in this RFC, with user message
interleaving is straightforward as it just requires the schedulers to
probe for the feature and ignore datamsg boundaries when dequeueing.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a helper to fetch the stream number from a given chunk.
Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the stream schedulers, sctp_stream_out will become too big to be
allocated by kmalloc and as we need to allocate with BH disabled, we
cannot use __vmalloc in sctp_stream_init().

This patch moves out the stats from sctp_stream_out to
sctp_stream_out_ext, which will be allocated only when the application
tries to sendmsg something on it.

Just the introduction of sctp_stream_out_ext would already fix the issue
described above by splitting the allocation in two. Moving the stats
to it also reduces the pressure on the allocator as we will ask for less
memory atomically when creating the socket and we will use GFP_KERNEL
later.

Then, for stream schedulers, we will just use sctp_stream_out_ext.
Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_socket_type_t, and
replace with enum sctp_socket_type in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_dbg_objcnt_entry_t, and
replace with struct sctp_dbg_objcnt_entry in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_cmsgs_t, and
replace with struct sctp_cmsgs in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_endpoint_type_t, and
replace with enum sctp_endpoint_type in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_sender_hb_info_t, and
replace with struct sctp_sender_hb_info in the places where it's
using this typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove this function typedef, there is even no places
using it.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_state_t, and
replace with enum sctp_state in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_xmit_t, and
replace with enum sctp_xmit in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_transport_cmd_t, and
replace with enum sctp_transport_cmd in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_scope_t, and
replace with enum sctp_scope in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_retransmit_reason_t, and
replace with enum sctp_retransmit_reason in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_lower_cwnd_t, and
replace with enum sctp_lower_cwnd in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_hmac_algo_param_t, and
replace with struct sctp_hmac_algo_param in the places where it's
using this typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_chunks_param_t, and
replace with struct sctp_chunks_param in the places where it's
using this typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_random_param_t, and
replace with struct sctp_random_param in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_init_chunk_t, and replace
with struct sctp_init_chunk in the places where it's using this
typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_paramhdr_t, and replace
with struct sctp_paramhdr in the places where it's using this
typedef.

It is also to fix some indents and  use sizeof(variable) instead
of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_cid_t, and replace
with struct sctp_cid in the places where it's using this
typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's a bad thing not to handle errors when updating asoc. The memory
allocation failure in any of the functions called in sctp_assoc_update()
would cause sctp to work unexpectedly.

This patch is to fix it by aborting the asoc and reporting the error when
any of these functions fails.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since last patch, sctp doesn't need to alloc memory for asoc->stream any
more. sctp_stream_new and sctp_stream_init both are used to alloc memory
for stream.in or stream.out, and their names are also confusing.

This patch is to merge them into sctp_stream_init, and only pass stream
and streamcnt parameters into it, instead of the whole asoc.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As Marcelo's suggestion, stream is a fixed size member of asoc and would
not grow with more streams. To avoid an allocation for it, this patch is
to define it as an object instead of pointer and update the places using
it, also create sctp_stream_update() called in sctp_assoc_update() to
migrate the stream info from one stream to another.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now sctp stream reconf will process a request again even if it's seqno is
less than asoc->strreset_inseq.

If one request has been done successfully and some data chunks have been
accepted and then a duplicated strreset out request comes, the streamin's
ssn will be cleared. It will cause that stream will never receive chunks
any more because of unsynchronized ssn. It allows a replay attack.

A similar issue also exists when processing addstrm out requests. It will
cause more extra streams being added.

This patch is to fix it by saving the last 2 results into asoc. When a
duplicated strreset out or addstrm out request is received, reply it with
bad seqno if it's seqno < asoc->strreset_inseq - 2, and reply it with the
result saved in asoc if it's seqno >= asoc->strreset_inseq - 2.

Note that it saves last 2 results instead of only last 1 result, because
two requests can be sent together in one chunk.

And note that when receiving a duplicated request, the receiver side will
still reply it even if the peer has received the response. It's safe, As
the response will be dropped by the peer.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is almost to revert commit 02f3d4ce ("sctp: Adjust PMTU
updates to accomodate route invalidation."). As t->asoc can't be NULL
in sctp_transport_update_pmtu, it could get sk from asoc, and no need
to pass sk into that function.

It is also to remove some duplicated codes from that function.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before when implementing sctp prsctp, SCTP_PR_STREAM_STATUS wasn't
added, as it needs to save abandoned_(un)sent for every stream.

After sctp stream reconf is added in sctp, assoc has structure
sctp_stream_out to save per stream info.

This patch is to add SCTP_PR_STREAM_STATUS by putting the prsctp
per stream statistics into sctp_stream_out.

v1->v2:
  fix an indent issue.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When sending a msg without asoc established, sctp will send INIT packet
first and then enqueue chunks.

Before receiving INIT_ACK, stream info is not yet alloced. But enqueuing
chunks needs to access stream info, like out stream state and out stream
cnt.

This patch is to fix it by allocing out stream info when initializing an
asoc, allocing in stream and re-allocing out stream when processing init.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

David Laight noticed the support for MSG_MORE with datamsg->force_delay
didn't really work as we expected, as the first msg with MSG_MORE set
would always block the following chunks' dequeuing.

This Patch is to rewrite it by saving the MSG_MORE flag into assoc as
David Laight suggested.

asoc->force_delay is used to save MSG_MORE flag before a msg is sent.
All chunks in queue would not be sent out if asoc->force_delay is set
by the msg with MSG_MORE flag, until a new msg without MSG_MORE flag
clears asoc->force_delay.

Note that this change would not affect the flush is generated by other
triggers, like asoc->state != ESTABLISHED, queue size > pmtu etc.

v1->v2:
  Not clear asoc->force_delay after sending the msg with MSG_MORE flag.

Fixes: 4ea0c32f ("sctp: add support for MSG_MORE")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NDavid Laight <david.laight@aculab.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>